where uranium and large amounts of mercury have been extracted . mines in what was called the op ##ali ##te mining district produced 270 @ , @ 000 fl ##ask ##s of mercury — " the richest supply of mercury in the western hemisphere " — from ci ##nna ##bar extracted from the calder ##a in the 20th century . the two leading mercury @ - @ producing mines in north america were the cord ##ero and mc ##der ##mit ##t mines on the edge of the calder ##a in nevada . together , they operated from 1933 to 1989 . the mc ##der ##mit ##t mine , the last mercury mine in the united states , closed three years later , in 1992 . however , mineral
where uranium and large amounts of mercury have been extracted. mines in what was called the opalite mining district produced 270 @, @ 000 flasks of mercury — " the richest supply of mercury in the western hemisphere " — from cinnabar extracted from the caldera in the 20th century. the two leading mercury @ - @ producing mines in north america were the cordero and mcdermitt mines on the edge of the caldera in nevada. together, they operated from 1933 to 1989. the mcdermitt mine, the last mercury mine in the united states, closed three years later, in 1992. however, mineral